Energy balance analysis of a stand-alone photovoltaic system, including variable system reliability impact

Official statistics estimate that almost two billion people have no direct access to electrical networks, 500,000 of them living in European Union and more than one tenth of them in Greece. An autonomous photovoltaic system is one of the most interesting and environmental friendly technological solutions for the electrification of remote consumers or entire rural areas. The primary objective of this current study is to determine the optimum dimensions of an appropriate stand-alone photovoltaic system, able to guarantee the coverage of remote consumers energy demand located in typical Greek territories using long-term measurements, under the restriction of minimum initial cost. Accordingly, the impact of acceptable reliability level on the stand-alone photovoltaic system energy behaviour and initial cost is also examined. Finally, special emphasis is laid on the detailed energy balance analysis of selected stand-alone photovoltaic system configurations, on an hourly basis at least. According to the results obtained, a properly sized stand-alone photovoltaic system is a motivating prospect for the energy demand problems of numerous existing isolated consumers all around Greece. (C) 2004 Elsevier Ltd. All rights reserved.